Grinding apparatus



Oct. 20'; 1931. w. N. APPLETON GRINDING APPARATUS Filed March 8. 1928 R O N E V m Patented Oct. 20, 1931 UNITED STATES PATENT OFFICE WALLACE N. APPLETON, OF GRAFTON, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO THE MCKAY COMPANY, OF PITTSBURGH, PENNSYLVANIA known in the art.

GRINDING APPARATUS Application filed March 8, 1928. Serial No. 260,206.

My invention relates to grinding apparatus, and more particularly to apparatus for grinding or surfacing metal or the like by means of an abrasive, and is hereinafter described as employed in connection with the grinding of metal bars, such as impact receiving bars of automobile bumpers, but it will be understood that the invention is susceptible of use in various other ways.

Oneobject of my invention is to provide means for carrying a bar or the like into op erative engagement with a grinding wheel and to thereafter automatically discharge the bar.

Another object ofmy invention is to provide an improved means for carrying the work into operative relation with a grinding element.

Still another object of my invention is to simplify and improve generally the structure and operation of grinding mechanisms.

One formwhich my invention may take is shown in the accompanying drawings, wherein Figure 1 is a side elevational view of the machine, showing a portion of the parts in section; Fig. 2 is a view, on an enlarged scale, taken on the line II-II of Fig. 1, and Fig. 3 is a view on an enlarged scale, taken on the line III-III of Fig. 1.

A framework or pedestal 4 is provided for supporting a head member 5 that has dovetail connection with the pedestal and which is slidably adjustable thereon by means of a handwheel 6, in any suitable manner well- A beam 7 is pivotally mounted upon the head '5 and carries at one end a grinding wheel 8. of emery or other suitable abrasive. The grinding wheel 8 is driven by the belt 9, from any suitable source of power, which belt extends substantially parallel to the beam 7 so that the beam may oscillate slightly without excessive stretching of the belt or seriously interfering with the driving function thereof.

That portion of the beam which carries the grinding wheel is heavier than the portion which is disposed at the opposite side of the pivotal mounting, and is partially counterbalanced by a tension spring 10 whose lower end is anchored to the base 4 and whose upper end is connected to an eye bolt 11. The eye bolt 11 is held in vertically adjustable position upon the beam 7 by nuts 12 and is adj ustable to permit variation of spring tension upon the beam. A stop screw 13 is adjustably connected to the head 5 to limit downward movement of the grinding wheel, so that it will not throw too great strain upon the belt 9 and so that the wheel will be properly positioned to permit passage of the work beneath the same.

The work carrier is mounted upon a base 14 and comprises a rotatable head or hub 15 that is driven by a belt 16 from a suitable source of power. The hub 15 is recessed for the reception of the work-holding devices that are each composed of gripping arms 17 which are of flat spring steel and held in place in the hub by bolts 18, each pair of gripping arms being formed integrally with one another. Set screws 19 are provided on the hub 15 for adjustably controlling expansive movement of the arms into work-holdirig position. i i i The work is represented as consisting of bumper bars 20, such as are employed in automobile bumper structures, the bars being shown ashaving eyes 21 formed in their outer ends. An operating lever 22 is pivotally mounted in each of three extensions 23 of the hub 15 and carries a pair of prongs 24 which overlie the outer faces of the gripping arms 17. It will be seen that when the lever 22 is rocked from the position shown at the right hand side of Fig. 1, the prongs 24 will draw the grippers 17 toward one another.

In operating the device, the grinding wheel 8 and the hub 15 are rotated in the direction indicated by the arrows, and the operator will press the lever 22 at the right hand side of Fig. 1, to draw the arms toward one another and then place the bumper bar 20 against the outer ends of the gripper arms 17 whereupon he will release the lever 22, allowing the gripper arms to expand for engagement with the eyes 21, at the ends of the bumper bar. The bumper bar is held against lateral displacement by means of yokes 25 that are rlveted to the arms 17. It will thus be seen that the bars 20 are securely held in place and will be carried into operative engagement with the grinding wheel and past the same to discharging osition. During the grinding operation, tfie head 5 may be shifted laterally by the hand wheel 6 to insure that all portions of the outer surface of the bumper bar will be acted upon b the grinding wheel.

When the bum er ar has been carried past the grinding wfieel, the lever 22 will be brought into engagement with a stop member 26 which will rock the same to cause the forks 24 to compress the gripping arms and release the bumper bar. The bumper bar is then ready for enamelling or plating, in the usualmanner, if desired.

I claim as my invention 2- 1. Grinding apparatus, comprising an abrading element, a rotatably-mounted carrier having a pair of gripping arms normally lying in expanded position, means for contracting said gripping arms to permit expansiion thereof into engagement with the work to be operated upon, and means for automatically contracting said arms to permit release of the work upon completion of a grinding o ration.

2. Grinding apparatus for bars each having longitudlnally-spaced offset portions on its inner side comprising an abrading element, a rotatable carrier, expansible gripping members rigidly secured on said carrier for engaging said offset portions and supporting the bar in a grinding position, and yoke members secured to the outer ends of said gripping members for supporting said bar against lateral di laeement.

3. Gri ing apparatus comprising an abrading element, a rotatable work carrier having a pair of gripping arms normally lying in expanded position, a pivotally mounted forked member having engagement with the outer faces of said arms, and means for rocking said forked member for simultaneously contracting said gripping arms to permit expansion thereof into engagement with the work to be operated upon.

' 4. Grinding apparatus for bars each having longitudinally-spaced offset portions on its inner side, comprising an abrading element, a rotatable carrier, a pair of straight Sided expansible gripping arms rigidly secured on said carrier. an extension on said carrier adjacent to said arms, a forked member pivotally mounted in the outer end of said extension with the prongs of said forked member overlying the sides of said arms, and means for rocking said member to contract said arms to permit expansion thereof into engagement with the said ofi'set portions of the bar.

5. Grinding apparatus for bars each having longitudinally-spaced offset portions on its inner side, comprising an abrading element, a rotatable carrier, expansible gripping arms rigidly secured on said carrier, an extension on said carrier adjacent to said arms, a forked member pivotally mounted on the outer end of said extension with the rongs of said forked member overlying the sides of said arms, a lever carried by said member for contracting said arms to permit expansion thereof into engagement with the said offset portions of the bar to support the bar for movement past said abrading element, and a stop member positioned to be engaged bysaid lever to rock said formed member upon completion of a grinding operation, thereby contracting said arms to release said bar.

6. Grinding apparatus for bars each having longitudinally-spaced ofl'set portions on its inner side, comprising an abrading eiement, a rotatable carrier havin a recess in the periphery thereof, expansible gripping arms of straight-sided loop form positioned in said recess, the free ends of the arms being bent outwardly for engaging the said offset portions and supporting the bar in a grinding position, and a bolt in the lower end of the recess and extending through the loop to hold the arms in said recess.

7. Grinding apparatus for bars each having longitudinally-spaced offset portions on its inner side, comprising an abrading element,

a rotatable carrier having a recess in the periphery thereof, expansible gripping arms of straight-sided loop form positioned in said recess, the free ends of the arms being bent outwardly for engaging the said offset portions and supporting the bar in a grinding position, and a bolt in the lower end of the recess and extending through the loop to hold the arms in said recess, the side walls of the recess extending along the sides of the arms to maintain the arms against lateral displacement.

8. Grinding apparatus for bumper bars, comprising a grinding wheel, a rotatable carrier. a recess in the periphery of the carrier, a pair of expansible gripping arms of straight sided loop form positioned in said recess, the free ends of said arms being expansible outwardly into gripping engagement with a bar, a pin engaging said loop to hold the said arms in the recess, and supporting means engaging the sides of said arms at points away from said loop to maintain the arms against lateral displacement.

9. Grinding apparatus for bars each having longitudinally-spaced ofiset portions on its inner sides, comprising an abrading element, a rotatable carrier, a recess in the periphery of the carrier, expansible gripping arms of straight-sided loop form rigidly secured in said recess, the free ends of said arms being expansible outwardly into gripping engagement with the said ofl'set portions of the bar, and adjustable means in the side walls of said recess engaging each of the said arms to adjustably control expansive movement of the arms into workholding position.

In testimony whereof I, the said WALLACE N. APPLETON, have hereunto set my hand. WALLACE N. APPLETON. 

